Spinal stabilization system

ABSTRACT

A spinal stabilization system is provided for maintaining preselected spacing and movement between adjacent vertebrae in a spinal column and for providing overall stability thereto. The system includes interlaminar members positioned in the spaces intermediate a first vertebra and the vertebrae positioned immediately above and immediately below and adjacent to the first vertebra. The interlaminar members are operatively connected to one another by an adjustable support structure and cooperate therewith to maintain the preselected spacing between adjacent vertebrae and to provide overall stability to the spinal column.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/209,138 filed on Mar. 13, 2014 which claims priority to U.S.Provisional Patent Application No. 61/794,543, filed on Mar. 15, 2013.This application also claims priority to U.S. Provisional PatentApplication 61/949,254 filed on Mar. 7, 2014, U.S. Provisional PatentApplication 61/939,484 filed on Feb. 13, 2014, U.S. Provisional PatentApplication 61/962,011 filed on Oct. 29, 2013, U.S. Provisional PatentApplication 61/883,398 filed on Sep. 27, 2013, and U.S. ProvisionalPatent Application 61/883,018 filed on Sep. 26, 2013. The entiredisclosures of each of the above-referenced patent applications areincorporated herein by reference as though set forth fully herein.

FIELD OF THE INVENTION

The present invention relates generally to the field of medicalapparatus and methods for using the same. More specifically, the presentinvention relates to systems and methods for treating spinal conditions,and specifically for systems for stabilizing vertebrae in the spinalcolumn. More specifically, the present invention relates to interlaminarvertebral stabilization devices for placement between adjacent vertebraand including supporting devices for stabilization of the vertebralsegments above and below the vertebra being treated.

BACKGROUND OF THE INVENTION

Injury to and/or diseases of the spine frequently result in damage to orabnormalities in the vertebrae, the intervertebral discs, the facetjoints and to the connective tissue and ligaments around the spine. Suchdamage or abnormalities may result in spinal instability causingmisalignment of the vertebral column and wear of the intervertebraldiscs and vertebral bony surfaces, a chronic and progressivedeterioration which typically results in severe pain, loss orrestriction of motion, and eventually, loss of mobility of theindividual suffering from the condition.

One treatment option for addressing spinal disorders is via surgicalintervention and the placement of fusion, stabilization and/or repairdevices on or adjacent to the spine or between adjacent vertebrae.Certain surgical procedures are irreversible, for example, fusiontechniques using bone grafts or synthetic implants to fuse vertebra, andmay also significantly alter vertebral range of motion. Otherprocedures, for example procedures for installing spinal implants orpedicle screw systems for fixating two or more vertebrae, are intricate,time consuming and highly invasive. Alternative solutions include theinsertion of interspinous or intra-laminar spacers in the space betweenadjacent vertebrae to control relative motion between and to stabilizethe two vertebrae. However, the stabilization does not extend above orbelow the insertion point, leaving the remaining portions of the spinalcolumn subject to unstable motion and the potential damage resultingtherefrom.

Various prior art systems have attempted to address the problemsdescribed above. U.S. Pat. No. 5,645,599 issued to Samani on Jul. 8,1997 (the '599 patent), discloses an interspinal implant device having agenerally u-shaped, spring-like configuration for insertion between thespinal processes of adjacent vertebrae. Samani's device includesopposing pairs of upwardly and downwardly extending brackets adapted tobe secured to the spinal process, thereby providing for flexiblepositioning of the adjacent vertebrae. However, the apparatus of the'599 patent does not attribute to the overall stability of the spinalcolumn; its effect being limited to the two specific vertebrae to whichit is attached. It is also difficult to attach multiple devicesconfigured in accordance with Samani's disclosure at adjacent segmentsdue to interference of the bracket portions.

Hochschuler et al disclose various intra-laminar stabilization systemsin U.S. Patent Application Publication No. US 2009/0204150 published onAug. 13, 2009 (the '150 publication), and in U.S. Patent ApplicationPublication No. US 2011/0106163 published on May 5, 2011 (the '163publication). The '150 publication discloses a pair of oppositelydisposed hook members that are translationally positioned on a rod andadapted to engage the laminar regions of adjacent vertebra and maintaina preselected spacing there between. However, the apparatus of the '150publication does not stabilize other vertebrae in the spinal column, itseffect being limited to the two adjacent vertebrae which it engages.

The Hochschuler et al. '163 publication discloses an interlaminarstabilizing system which includes a structure adapted to be disposedbetween two adjacent vertebrae as described above with respect to theapparatus of the '150 publication. The '163 structure further includes asupport structure which is secured to the second vertebra to furtherrestrict the interval spacing between the adjacent vertebrae. However,the system of the '163 disclosure also does not stabilize the vertebraein the remaining portions of the spinal column for the reasons set forthabove.

Moreover, none of the known prior art systems address the problem of“transition syndrome” or “adjacent segment disease” associated withfusion of adjacent vertebrae. In fusion, if a motion segment iseliminated via fusion, the unfused adjacent segments above and below thefused vertebrae take up and bear the additional forces induced bybending and rotational movement of the spine, which may result inso-called “transition syndrome” over the long term. In addition, none ofthe prior art systems provide for augmenting previously installed spinalhardware to enhance stability, adjust intervertebral distraction, and soforth.

Accordingly, a need exists for an improved spinal stabilization systemwhich provides both flexibility and stability to the spinal column andwhich addresses the combination of problems not solved by the prior art.

SUMMARY OF THE INVENTION

In order to achieve the above-mentioned objectives, the presentinvention provides an improved spinal stabilization system formaintaining preselected spacing and movement between adjacent vertebraeand also which provides overall stability to the spinal column.

In one embodiment, a spinal stabilization system is provided whichincludes at least one interlaminar member adapted to be inserted betweentwo adjacent vertebrae and a stabilizing structure for stabilizing thevertebrae at least one layer above and below the two adjacent vertebrae.

In another embodiment, a spinal stabilization system is provided whichincludes a blocking member to limit movement of adjacent vertebrae toprevent narrowing of the spinal canal and nerve compression.

In yet another embodiment, a spinal stabilization system is providedwhich includes at least one adjustable cross-linking member to enhancestability of the spine.

These and other objects, features, aspects and advantages of the presentinvention will be apparent from the accompanying detailed description ofthe invention, which, taken with the appended drawings, discloses apreferred and alternate embodiments thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front plan view of a spinal stabilization system inaccordance with an embodiment of the present invention;

FIG. 2 is a side perspective view of a spinal stabilization system inaccordance with an embodiment of the present invention;

FIG. 3 is a side plan view of a spinal stabilization system inaccordance with an embodiment of the present invention;

FIG. 4 is a bottom perspective view of a spinal stabilization system ofthe present invention;

FIG. 5 is a top perspective view of a spinal stabilization system inaccordance with an embodiment of the present invention;

FIG. 6 is an enlarged side plan view of a portion of the spinalstabilization system of the present invention shown in FIG. 3 showing anupper portion of the stabilization system affixed to a spinal column;

FIG. 7 is a side perspective view of a portion of the spinalstabilization system shown in FIG. 6;

FIG. 8 is an exploded front perspective view of a portion of the spinalstabilization system shown in FIGS. 6 and 7;

FIG. 9 is a rear perspective view of a portion of the spinalstabilization system shown in FIGS. 6, 7 and 8;

FIG. 10 is a front plan view of a spinal stabilization system inaccordance with an embodiment of the present invention affixed to aspinal column;

FIG. 11 is a bottom front perspective view of a spinal stabilizationsystem in accordance with an embodiment of the present invention affixedto a spinal column;

FIG. 12 is a top front perspective view of a spinal stabilization systemin accordance with and embodiment of the present invention affixed to aspinal column;

FIG. 13 is a side perspective view of a spinal stabilization system inaccordance with an embodiment of the present invention affixed to aspinal column;

FIG. 14(A) is a rear side perspective view of an interlaminar portion ofa spinal stabilization system in accordance with an embodiment;

FIG. 14(B) is a side plan view of the interlaminar portion of a spinalstabilization system shown in FIG. 14(A);

FIG. 14(C) is a front plan view of the interlaminar portion of a spinalstabilization system shown in FIGS. 14(A) and 14(B);

FIG. 15 is a top front perspective view of a spinal stabilization systemin accordance with an embodiment of the present invention;

FIG. 16 is a bottom front perspective view of the spinal stabilizationsystem shown in FIG. 15;

FIG. 17(A) is a top front view of a spinal stabilization system inaccordance with an embodiment of the present invention;

FIG. 17(B) is a bottom rear perspective view of the spinal stabilizationsystem shown in FIG. 17(A);

FIG. 18 is a bottom front perspective view of a spinal stabilizationsystem in accordance with an embodiment of the present invention;

FIG. 19(A) is a top front perspective view of the spinal stabilizationsystem shown in FIG. 18;

FIG. 19(B) is a front side perspective view of portions of the spinalstabilization system shown in FIGS. 18 and 19(A);

FIG. 19(C) is a rear side perspective view of portions of the spinalstabilization system shown in FIGS. 18, 19(A) and 19(B);

FIG. 20 is a partial sectional side perspective view of portions of thespinal stabilization system shown in FIG. 1;

FIG. 21 is a rear perspective view of a spinal stabilization system inaccordance with an embodiment of the present invention affixed to aspinal column;

FIG. 22 is a front perspective view of the spinal stabilization systemshown in FIG. 21;

FIG. 23(A) is a front perspective view of the spinal stabilizationsystem shown in FIG. 22 with additional elements shown affixed to aspinal column;

FIG. 23(B) is a front perspective view an alternate embodiment of thespinal stabilization system shown in FIG. 23(A) with additional elementsshown affixed to a spinal column;

FIG. 24 is a side perspective view of a spinal stabilization system aspinal stabilization system in accordance with an embodiment of thepresent invention shown affixed to a spinal column;

FIG. 25 is a rear side perspective view of a spinal stabilization systemin accordance with an embodiment of the present invention;

FIG. 26 is a front side perspective view of the spinal stabilizationsystem shown in FIG. 25;

FIG. 27(A) is a side perspective view of portions of the spinalstabilization system shown in FIGS. 25 and 26;

FIG. 27(B) is a left partial sectional side perspective view of portionsof the spinal stabilization system shown in FIGS. 25 and 26;

FIG. 27(C) is a right partial sectional side perspective view ofportions of the spinal stabilization system shown in FIGS. 25 and 26;

FIG. 28 is a lower side perspective view of a spinal stabilizationsystem in accordance with an embodiment of the present invention;

FIG. 29 is a bottom front perspective view of the spinal stabilizationsystem shown in FIG. 28;

FIG. 30 is a side view of the spinal stabilization system of FIG. 28shown affixed to a spinal column;

FIG. 31 is a front view of the spinal stabilization system shown in FIG.30;

FIG. 32 is a side perspective view of a spinal stabilization a spinalstabilization system in accordance with an embodiment of the presentinvention shown affixed to a spinal column;

FIG. 33 is a front perspective view of the spinal stabilization systemshown in FIG. 32,

FIG. 34(A) is a side view of an element of a spinal stabilization systemin accordance with an embodiment of the present invention;

FIG. 34(B) is a top view of an element of the spinal stabilizationsystem shown in FIG. 34(A);

FIG. 34(C) is a right perspective side sectional view of an element ofthe spinal stabilization system shown in FIGS. 34(A) and 34(B);

FIG. 34(D) is a top sectional view of an element of the spinalstabilization system shown in FIGS. 34(A), 34(B) and 34(C);

FIG. 35(A) is a top perspective view of an element of a spinalstabilization system in accordance with an embodiment of the presentinvention;

FIG. 35(B) is a bottom perspective view of an element of the spinalstabilization system shown in FIG. 35(A);

FIG. 35(C) is a side view of an element of the spinal stabilizationsystem shown in FIGS. 35(A) and 35(B);

FIG. 36(A) is a top perspective view of an element of a spinalstabilization system in accordance with an embodiment of the presentinvention;

FIG. 36(B) is a bottom perspective view of an element of the spinalstabilization system shown in FIG. 36(A);

FIG. 36(C) is a side view of an element of the spinal stabilizationsystem shown in FIGS. 36(A) and 36(B);

FIG. 37(A) is a side view of an element of a spinal stabilization systeminsertion tool in accordance with an embodiment of the presentinvention;

FIG. 37(B) is a side view of an element of an insertion tool forinstalling a portion of a spinal stabilization in accordance with anembodiment;

FIG. 37(C) is a side view of another insertion tool for installing aportion of a spinal stabilization system in accordance with anembodiment;

FIG. 37(D) is a side sectional view of the element of a spinalstabilization system and the insertion tools therefor shown in FIGS.37(A), 37(B) and 37(C), respectively;

FIG. 38 is a top view of the insertion tool of FIG. 37(A)-(D) shown inoperative engagement with an element of a spinal stabilization system inaccordance with an embodiment of the present invention;

FIG. 39 is a sectional perspective view of the insertion tool shown inFIG. 38;

FIG. 40 is a top perspective view of a spinal stabilization systeminsertion tool in accordance with an embodiment of the presentinvention;

FIG. 41(A) is a perspective view of portions of the insertion tool shownin FIG. 40;

FIG. 41(B) are enlarged perspective views of portions of the insertiontool shown in FIGS. 40 and 41(A);

FIG. 42(A) is a side plan view of a spinal stabilization insertion toolin accordance with an embodiment of the present invention;

FIG. 42(B) is a side sectional view of the insertion tool shown in FIG.42(A);

FIG. 43 is a side view of the insertion tools of FIGS. 37-42 shown inoperative engagement with a spinal stabilization system in accordancewith an embodiment of the present invention;

FIG. 44 is a side perspective view of the insertion tools shown in FIG.43;

FIG. 45 is a top perspective view of the insertion tools shown in FIGS.43 and 44; and

FIG. 46 is an enlarged perspective view of portions of the tools of FIG.45.

DESCRIPTION OF THE INVENTION

It should be noted that the present description is by way ofillustration only, and that the concepts and examples presented hereinare not limited to use or application with any single system ormethodology. Hence, while the details of the system and methodsdescribed herein are for the convenience of illustration and explanationwith respect to the exemplary embodiments, the principles disclosed maybe applied to other types of spinal stabilization systems withoutdeparting from the scope of the present invention.

Referring now to FIG. 1, a spinal stabilization system according to anembodiment of the present invention is shown generally at 10 (which forpurposes of brevity will be referred to herein as “the system”). Thesystem includes a first interlaminar member 12 adapted to be positionedbetween adjacent vertebra in a spinal column. As shown in greater detailin FIGS. 6 and 7, the interlaminar member 12 is shown positioned betweena first vertebra 14 and a second adjacent vertebra 16 in a spinal column18.

The system further includes a second interlaminar member 20 adapted tobe positioned between the second vertebra 16 and a third vertebra 22 inthe spinal column 18. While the system 10 of the embodiment of FIG. 1 isdescribed with reference to two interlaminar support members, it is tobe understood that a third, fourth or more interlaminar support membersor components may be coupled to the system to permit stabilization orfixation of additional spinal segments in either or both directionsalong a patent's spinal column.

Both the first and second interlaminar members are operatively connectedto a support structure shown generally at numeral 25 in FIG. 1. By wayof example, in the embodiment shown, the support structure and the firstinterlaminar member are integrally formed from a single piece ofmaterial such as titanium or stainless steel suitable for use as amedical implant device. However, it is to be understood that other meansfor connecting the interlaminar device to the support structure such ashinges, pins, threaded fasteners and the like may also be used withoutdeparting from the scope of the invention.

The support structure 25 comprises a pair of support members or guiderods 28 secured to the first interlaminar support member 12 andextending in a direction upwardly therefrom substantially parallel toone another. In the embodiment shown, guide rods 28 are of an exemplarygenerally circular cross-sectional configuration. However, it is to beunderstood that other structured shapes such as oval square, hexagonal,and I-beam cross sections may also be used with equal efficiency.

The second interlaminar member 20 includes a body portion 21 of apreselected thickness t, which is most clearly illustrated in FIGS. 3and 9. Thickness t is selected based upon the spacing between the secondand third vertebrae and may be smaller in size than the spacing to allowfor flexion or extension of the spinal column 18. Alternatively, it maybe sized for interference fit between the laminae/spinous processes. Thebody portion 20 may take many variations in size, scope, and physicalproperties such as hardness, flexibility, and so forth, depending uponthe patient's anatomical structure and the problems being addressed.

The body portion 21 further includes a pair of oppositely positionedears 30 extending laterally outwardly from the body portion in opposingdirections, each of the ears containing an aperture 32 structured andarranged to slideably receive one of the support members or guide rods28. As will be discussed in greater detail below, the secondinterlaminar member is movably supported by upwardly extending supportmembers or guide rods, and the position of the second interlaminarmember 20 relative to the first interlaminar member 12 may be adjusteddepending upon the dimensions of the specific spinal column on which thesystem is installed and the range of motion desired. Once the positionof the second interlaminar member 20 has been selected, it is locked inplace by a pair of set screws or other suitable fastening means 34extending through each of the ears 30 and adapted to releaseably engagethe respective guide rod extending therethrough, as shown in FIG. 1 andin greater detail in FIG. 4.

Referring now to FIGS. 2, 3, 7 and 8, the first interlaminar member 12is depicted in greater detail. The first interlaminar member comprises abody 40 defined by an elastic midsection 42, two spaced apart endportions 44, and a pair of juxtaposed legs 46, each leg extendingsubstantially parallel to one another from one of the respective ends ina direction generally outwardly away from the spinal column 18 (FIG. 7)and spaced apart a preselected distance d. Distance d is determined bythe size of the first interlaminar member, which, in turn, may beselected based upon the spacing between the first and second vertebrae14 and 16 respectively. Depending upon the situation, the firstinterlaminar member may be intended to fuse the first and secondvertebrae, or it may be intended to permit limited motion therebetweenwhile at the same time maintaining the stability of vertebra 16 relativeto vertebra 14. Accordingly, it is sized to be a tight fit, and theelastic properties of the body 40 act as a spring or shock absorber inthe interface between the two vertebrae. In the embodiment shown in theabove-referenced figures, the elastic midsection 42 of the body 40 isU-shaped. However, other shapes or configurations, by way of example, aV-shape, a W-shape or other function configurations may also be usedeffectively. Further, the uppermost one of the legs 46 is longer thanthe lower one of the legs, thereby forming a handle 48 which may be usedto insert and position the system during surgery and also to increasethe contact surface area with the adjacent spinous process. As notedabove, depending upon the problem being addressed, the U-shaped body maybe rigid or flexible.

Referring again to FIG. 1, the support structure 25 further includes aT-shaped frame member 50 operatively connected to the first and secondinterlaminar members 12 and 20 and which extends generally downwardlytherefrom in a direction substantially parallel to the spinal column 18.The T-shaped frame member includes an elongate body 52 having first andsecond end portions 54, 56, the first end portion being operativelyconnected to the first interlaminar member 12, and an elongate crossmember 58. The cross member has first and second end portions 60, 62 anda midpoint 64 and is structured and arranged to be connected to thesecond end portion 56 of the body 52 at approximately the midpoint 64.Each of the ends 60, 62 of the cross member 58 are adapted to receiveand adjustably secure first and second support members 66 and 68respectively. In the embodiment shown, each of the end portions 60, 62has an aperture 70, 72 formed therein respectively for receiving one ofthe support members 66, 68, each of which may be held in a preselectedposition by a set screw 74 or other interconnecting coupling means as isknown in the art.

In the embodiment shown, by way of example only and not of limitation,the support members are in the form of spinal or guide rods 66, 68, eachguide rod having an upper end 76 and a lower end 78. Each of the upperand lower ends of the support members 66, 68 has a securing device 80slideably positioned thereon and adapted to be secured thereto by meansof set screws 82. By way of example, each of the securing devices 80 isadapted to receive a pedicle screw 84, each pedicle screw beingstructured and arranged to be secured to one of the vertebra of thespinal column 18.

The installation and operation of the spinal support system 10 of thepresent invention are illustrated in greater detail in FIGS. 6, 7 and10-13. The system advantageously may be installed where other spinalfixation or fusion devices or similar medical apparatus are already inplace to add stability to the spinal column above and below theinstallation point, to control flexion, extension, axial compression,and/or rotational movement of the spine or selected vertebrae withrespect to one another, and to prevent impingement of adjacentvertebrae, spinal processes, pedicle screws and medical hardware on oneanother. By way of example, as best shown in FIGS. 6 and 7, a surgeonmay insert the system 25 into the space between adjacent vertebrae 14and 16 by gripping handle 48 and making the insertion. The tight fittingU-shaped body 40 not only serves to control any motion between theadjacent vertebrae or even eliminate it entirely, thereby effectivelystabilizing or fixating the vertebrae, but also serves as a dampeningcushion or spring device by virtue of the spring-like elasticity of thebody 40 translated to the vertebrae via legs 46. Thereafter, the secondinterlaminar member 20 may be selectively positioned intermediatevertebra 16 and vertebra 22 to permit flexion on a forward direction butto limit extension in the rearward direction and to limit compression ofthe spinal segment, thereby imparting enhanced stability to the spinalcolumn above the fused vertebrae.

In the embodiment of FIG. 7, the body 40 of interlaminar member 12 isformed integrally with those portions of the system 10 above and belowit, it is to be understood that it could comprise a separate element ofthe system and be adjustably moveable inwardly by rack and piniongearing or ratcheting devices to provide a precise fit in theinterlaminar space between vertebrae 14 and 16 positioned as closely tothe spinal canal as safety considerations permit. The upper leg andhandle 48 extending therefrom may be longer than the lower leg 46,whereby the contact surface area engaging the spinal process 17positioned there above, is enlarged. This structure effectivelydistributes the associated forces over a larger surface contact area,thereby reducing the risk of fracture of the spinal process.

In a similar manner, support structure 25, via the T-shaped frame member50 and support members or guide rods 66 and 68, provides support to theportion of the spinal column located below the fused vertebrae 14 and16. As shown in FIGS. 10-13, the securing devices 80, which are coupledto heads of pedicle screws 84 (not shown), may be positioned in firstvertebra 14 and in either vertebra 15 immediately adjacent to vertebra14, and/or at a lower level as shown by vertebra 17, thus extending thestabilizing effect of the novel support system of the present inventionto multiple levels in the spinal column 18. More than one level may beaddressed simply by lengthening the rods 66 and 68 and slideablypositioning multiple securing devices 80 thereon for selectivepositioning along the spinal column.

In one aspect of the present invention, elongate body 52 may becomprised of multiple pieces. For example, one or more linear racks maybe configured in operable relation with gear mechanisms, thereby forminga ratchet device (not shown), in order to extend the distance betweenfirst and second end portions 54 and 56 thereby permitting a surgeonduring the course of the surgical procedure to adjust and aligncomponents of the implant in relation to the patient's bony anatomy andsubsequently securing them in place. For example, a ratchet mechanismconfiguration may permit the surgeon to progressively extend elements ofthe implant to better oppose a lamina, e.g., after 60/62 are secured to66/68.

In another aspect, the cross member midpoint 64 may be configured to beadjustably (e.g., pivotably or translatably) connected or secured to thesecond end portion 56 of the body 52 at approximately the midpoint 64 inorder to allow a surgeon during the course of the surgical procedure toadjust and align components of the implant in relation to the patient'sbony anatomy and in relation to support members 66 and 68. By way ofexample and not of limitation, FIGS. 14(A)-(C) illustrate aninterlaminar member 90 adapted to be positioned between adjacentvertebra in a spinal column. The interlaminar member includes a bodyportion 92 having a first end portion 94 and a second end portion 96,the second end portion being structured and arranged to adjustablyreceive the elongate cross member 58 (FIG. 1) in order to allow asurgeon to further adjust and align components of the implant inrelation to the patient's bony anatomy. By way of example and not oflimitation, the second end portion 96 may include an open-ended apertureor channel 98 for receiving and selectively positioning the elongatemember 58 and a means for securing the elongate member in a desiredposition along a patient's spinal process. The elongate cross member 58may have a cross-sectional configuration which is complementary to thecross section of the channel or aperture, be it rectangular, hexagonal,circular, or another shape.

In the embodiment shown, the securing means includes an aperture 99formed transversely in the channel 98 and adapted to receive a lockingmechanism, e.g., one or more set screws, clamps, pins, pegs and the likesuch that when the locking mechanism is engaged, the second end portion96 is in a fixed relation to the elongate cross member 58. Thisconfiguration may permit translational and/or rotational movement(s)between the second end portion and the elongate cross member to permitalignment of the various elements of the spinal stabilization system 10(FIG. 1) with a patient's unique anatomical structure, and, followingalignment, the locking mechanism may be engaged to fix the relativeposition of the system components with respect to one another and withrespect to the spinal process.

According to particular embodiments, interlaminar member 20 may beconfigured to permit connection to guide rods 28 via an approach that issubstantially perpendicular to the longitudinal axis of guide rods 28.In other words, after the other components of the system have beenimplanted via a posterior approach to the posterior aspect of the spinethe interlaminar member 20 may follow a generally similar approachtrajectory and then secured to the guide rods 28 with, e.g., set screwsin a similar manner to the engagement between the ends 60, 62 of thecross member 58 and first and second support members 66 and 68.Furthermore, in another aspect, an interlaminar member 20 may be usedalone (and may alternatively be configured to be similar to the U-shapedbody 40) and may be directly engaged with a first and second supportmembers 66 and 68 and positioned between the lamina and spinousprocesses of the spine.

In yet another aspect, each of the ends 60, 62 of the cross member 58may be configured to permit a degree of adjustability (e.g., pivotablyor translatably) to receive and adjustably secure first and secondsupport members 66 and 68 respectively. For example any transverseconnector or cross-link variable adjustment mechanism or fastener knownin the art may be employed to accomplish the desired fixation betweenthe ends 60, 62 of the cross member 58 and first and second supportmembers 66 and 68. A spinal stabilization system 100 incorporating thesefeatures is illustrated generally at 100 in FIGS. 15 and 16.

System 100 includes an interlaminar member 102 of substantially the sameconfiguration as the interlaminar member 12 described above in theembodiment of FIG. 1. Interlaminar member 102 is adapted to bepositioned between adjacent vertebra in a spinal column and isoperatively connected to a support structure shown generally at numeral104. As described hereinabove with respect to the embodiment of FIG. 1,in the embodiment shown in FIGS. 15 and 16, the support structure andthe interlaminar member are integrally formed from a single piece ofmaterial such as titanium or stainless steel suitable for use as amedical implant device. However, it is to be understood that other meansfor connecting the interlaminar device to the support structure such ashinges, pins, threaded fasteners and the like may also be used withoutdeparting from the scope of the invention.

The support structure 104 comprises a pair of spaced-apart supportmembers or guide rods 106 secured to the interlaminar member 102 andextending in a direction upwardly therefrom substantially parallel toone another. Each of the guide rods 106 includes an ear or bracketelement 108 extending generally outwardly therefrom in a directioneither toward or away from the spinal column (not shown) and includes anaperture 110 formed therein adapted to receive a securing device such asa pin or a threaded fastener for attaching the system to a vertebra.

While not shown in the drawings, it is to be understood that the guiderods 106 and ear or bracelet elements 108 connected thereto may beadjustably moveable by a ratcheting or other suitable mechanism in adirection towards each other, thereby applying a clamping force to aspinal process positioned therebetween. Each of an inner surfaced orface 109 may also include a rough textured finish or have sharpextensions, or “spikes” (not shown) formed thereon and extendingoutwardly therefrom which may imbed themselves in the surface of aspinal process, thereby preventing slippage.

In a similar manner, ridges 111 formed on an upper surface 113 of number102 also engage the bony structure of a vertebra, thereby enhancing theengagement of the system 100 with the spinal column.

The support structure 104 further includes an elongate body 112 havingfirst and second end portions 114, 116, the first end portion beingoperatively connected to interlaminar member 102; the second end portionbeing operatively connected to a pair of elongate cross members 118adjustably positioned in overlapping juxtaposition with respect to oneanother and the second end portion 116 of the support structure, as willbe described hereinbelow in greater detail. Each of the cross membershas first and second end portions 120, 122, each of the first endportions 120 having a longitudinally extending aperture or slot 124formed therein, and each of the second end portions includes a connector126 adapted to receive and adjustably secure a support member of thesystem, such as a guide rod 66, 68 as illustrated in FIG. 1, by alocking member 128. Locking member 128 may be in the form of a setscrew, a pin, a clamp or other such suitable locking means as is knowngenerally in the art.

As shown in greater detail in FIG. 16, the second end portion 116 has anelongate longitudinally extending aperture or slot 130 formed thereinstructured and arranged to receive securing means shown generally at 134for adjustably securing elongate cross members 118 thereto. By way ofexample and not of limitation, securing means 134 includes a collar 136slideably positioned on end 116 and having a generally transverselyextending aperture 138 formed therein for receiving a first end portion120 of an elongate cross member 118. A fastener, by way of example abolt 140, extends through each of the slots 124 in the elongate crossmembers 118 placed in overlapping slideable juxtaposition with respectto one another, the slot 130 in the second end 116 of the supportstructure 104 and into an aperture, by way of example a threadedaperture (not shown) which is formed in the collar 136. Thisconfiguration permits translational and/or rotational movement andadjustment in the generally caudal or cephalad directions of both thefirst and second ends 120, 122 of the cross members 118 with respect tothe elongate body 112, thereby permitting precise alignment of theinterlaminar member 102 with a lamina and spinal process. Thereafter,the locking mechanism is engaged to fix the elements of the system inposition with respect to one another and the patient's spine. While notshown in the figures, a second locking mechanism or stop such as a pin,strap, a band, a fastener, a clamp, and the like, as is known in theart, may also be connected to the elongate cross members 118 after theyand the other elements of the system are aligned and fastener 140 istightened to prevent movement of the elongate cross members relative toone another in response to loading transmitted thereto via the elongatebody 112. This would be of particular concern in the event that thesecuring means 134 would loosen after installation.

Referring now to FIGS. 17(A) and (B), an embodiment 150 of a spinalstabilization system of the present invention is illustrated whichincludes a support structure 152 having an elongate body in the form ofa rod or dowel 154 having first and second end portions 156, 158, thefirst end portion being operatively connected to interlaminar member102; the second end portion being operatively connected to a pair ofelongate cross members 118 adjustably positioned in overlappingjuxtaposition with respect to one another and the second end portion 158of the support structure, as described above with respect to theembodiment of FIGS. 15 and 16. However, in the embodiment of FIG. 17, asecuring means 160 is provided in the form of a spherical or tubularcollet 162 received over the first end portion 156 and secured theretoby a collar 164 and setscrew 166 or other suitable means of applying acompressive restraining force to the collet 162. The securing means 160provides both translational and rotational movement of the interlaminarmember 102 with respect to the support system 152, thereby permittingvery precise alignment of the interlaminar member with a lamina andspinal process.

A second similar securing means 168 having a spherical or tubular collet170 received over the second end portion 158 of rod 154 and securedthereto by a collar 172 and setscrew or other suitable compressivesecuring means (not shown) applies a compressive restraining force tothe collet 162. In the manner described above with respect to the colletand securing means at the first end 156, the collet 170 provides bothtranslational and rotational movement of the overlapping elongate crossmembers 118 with respect to the rod 154 and interlaminar member 102,thereby assisting in establishing very precise alignment of theinterlaminar member with a lamina and spinal process. In the embodimentshown, collets 170 are mounted on collar 172 of securing means 168.However, for enhanced stability, the collets could also be mounted ontransverse cross members, such as members 314 as shown in FIG. 24,instead.

In the embodiment of FIGS. 17(A) and (B), the each of the second endportions 122 of the overlapping elongate cross members 118 includes aconnector adapted to receive and adjustably secure a support member ofthe system, such as a guide rod 66, 68 as illustrated in FIG. 1, ashereinabove described. In the embodiment of FIGS. 17(A) and (B), theconnector is shown in the form of a compressible collet 174 extendingcircumferentially around the guide rod and releaseably secured inposition by a compression nut 176 or other suitable locking meanssecured thereto.

In an embodiment 190 of the spinal stabilization system of the presentinvention as shown in FIGS. 18-23(A) and 23(B), the elongate body of thesupport structure as described in exemplary form above with respect tothe embodiments of FIGS. 1-17 is depicted in the form of at least twoelongate body members, by way of example, rods or dowels 192. Each rodincludes a first and a second end 194, 196; each first end 194 beingstructured and arranged to be connected to an interlaminar supportmember 198 and each second end 196 being operatively connected to a pairof elongate cross members 118 adjustably positioned in overlappingjuxtaposition with respect to one another, as described in detail above.The spherical or tubular collets 170 provide a pivotal connection of therods to the members 118 so that each of the rods may be individuallymovable in any direction relative to one another and to a patient'svertebrae 14, 15, 16 and 22, as shown in FIGS. 21 and 22. Alternatively,the rods may be tied together by a transversely extending crosspiece(not shown) so that the rods may be movable relative to the crossmembers 118, yet not moveable relative to one another, therebyfacilitating the positioning and attachment of one or more interlaminarsupport members 198 thereto by suitable connections such as set screws199 threadably inserted into apertures 200 formed in the interlaminarsupport member as shown in FIGS. 18, 19, 20 and 23.

In the embodiment of FIG. 23(A), the interlaminar support members 198are shown installed with a leg 46 that is not attached directly to a rod192 positioned on the side closest to the transverse cross members 118,thereby directing the spring forces from the cross members relativelyuniformly into the adjacent vertebrae 22, 16 and 14. However, withreference to the embodiment of FIG. 23(B), by installing the supportmembers such that they face each other, the spring forces are directedinto vertebra 16, thereby compressing it in this application.

Referring now to FIGS. 24-27, a spinal stabilization system 300 of thepresent invention is illustrated according to an embodiment whichincludes a support structure 310 structured and arranged to secure thesystem to a patient's spinal process or column 312 to stabilize multiplelevels of vertebra 15, 14, 16, and 22, in ascending order. The supportstructure 310 includes a plurality of transversely extending elongatecross members 314 adjustably positioned one above the other in generalalignment with the spinal column 312. In the embodiment shown, by way ofexample and not of limitation, the cross members are in the form of apair of transversely extending rods which spans the spinal column.However, it is to be understood that three or more cross members ofvarious shapes and configurations may also be used without departingfrom the scope of the present invention. In the embodiment of FIG. 24,an intervertebral body fusion device (“IBFD”) 311 is shown insertedbetween each of the adjacent vertebrae 15, 14; vertebrae 14, 16; andvertebrae 16, 22 to provide additional stability to the spinal column312.

As shown in greater detail in FIGS. 25 and 26, each cross member 314comprises an elongate body 316 having first and second end portions 318,320 and a midpoint 322 and is structured and arranged to be operativelyconnected at approximately the midpoint to a first interlaminar supportmember 325. Each of the ends 318, 320 of the cross members are adaptedto receive a connector or securing device 326 for adjustably securingfirst and second support members 66 and 68 respectively, as describedabove with respect to other embodiments of the present invention and ingreater detail below.

FIG. 27 illustrates the elements of each connector 326 in greaterdetail. Each connector has an aperture 328 formed therein respectivelyfor receiving one of the ends 318, 320 of the elongate body portion 316of cross member 314, each of which may be held in a preselected positionby a set screw or other fastening means 330. Each connector furtherincludes a retainer or bracket element 331, which, in the embodimentshown, is in a generally J or hook shaped configuration adapted toconform to the shape of the support members 66, 68; however, otherconfigurations and shapes may also be employed to adapt to theconfigurations of the support members which may be used. In theembodiment shown, by way of example only and not of limitation, thesupport members are in the form of guide rods 66, 68, each guide rodhaving an upper end 332 and a lower end 334. The guide rods 66, 68 maybe secured following alignment and adjustment of the system 300 to apatient's anatomy and spinal structure (as shown generally in FIG. 24)by pressure transmitted from a respective set screw 330 via an end of across member 320 indicated by arrow 333 in FIG. 27(C).

Each of the upper and lower ends of the support members 66, 68 has asecuring device 336 slideably positioned thereon and adapted to besecured thereto by means of set screws 338. By way of example, each ofthe securing devices 336 is adapted to receive a bone screw 340, eachbone screw being structured and arranged to be secured to one of thevertebra of the spinal column 312.

Referring again to FIGS. 25 and 26, the elements of the interlaminarsupport member 325 and other elements of the support system 300 aredisclosed in further detail. Similar in construction to the embodimentof the system of FIG. 1, interlaminar member 325 is adapted to bepositioned between adjacent vertebrae in a spinal column. As shown ingreater detail in FIG. 24, the interlaminar member 325 is shownpositioned between a first vertebra 16 and a second adjacent vertebra 22in a spinal column 312.

The system further includes a second interlaminar member 341 adapted tobe positioned between the second vertebra 22 and a third vertebra 23 inthe spinal column 312. Both the first and second interlaminar membersare operatively connected to a support structure shown generally atnumeral 342. By way of example, in the embodiment shown, the supportstructure 342 and the first interlaminar member 325 are integrallyformed from a single piece of material such as titanium or stainlesssteel suitable for use as a medical implant device, and the interlaminarstructure 325 may be welded at 344 to one of the cross members 314.However, it is to be understood that other means for forming and/orinterconnecting the various elements of the system such as hinges, pins,threaded fasteners, casting techniques and the like may also be usedwithout departing from the scope of the invention.

Interlaminar member 325 comprises a U-shaped body 346 defined by anelastic midsection 348, two spaced apart end portions 350, and a pair ofjuxtaposed legs 352, each leg extending substantially parallel to oneanother from one of the respective ends in a direction generallyoutwardly away from the spinal column 312 and spaced apart a preselecteddistance d (FIG. 24). Distance d is determined by the size of theinterlaminar member 325, which is, in turn, is selected based upon thespacing between the vertebrae 16 and 22, respectively. The interlaminarmember is intended to fuse the vertebrae. Accordingly, it is sized to bea tight fit, and the elastic properties of the U-shaped body 348 act asa spring or shock absorber in the interface between the two vertebrae.Further, the uppermost one of the legs 352 may be used as a handle toinsert and position the system during surgery.

As discussed above with respect to the embodiment of FIG. 1, while thebody 346 is described as being U-shaped, it is to be understood thatmany other shapes and configurations may also be effectively employedwithout departing from the scope of the present invention. It is also tobe noted that both interlaminar members 325 and 341 include pointedridges or teeth 327 extending outwardly therefrom which are adapted toengage portions of vertebra 22 positioned therebetween to preventslippage of the stabilization system 300 following installation.

The system 300 further comprises a pair of support members or guide rods354 secured to the interlaminar support member 325 and extending in adirection upwardly therefrom substantially parallel to one another. Thesecond interlaminar member 341 includes a body portion 356 of apreselected thickness t, which is selected based upon the spacingbetween vertebrae 22 and 23, and is intended to be smaller in size thanthe spacing to allow for flexion of the spinal column 312.

The body portion 356 further includes a pair of oppositely positionedears 358 extending laterally outwardly from the body portion in opposingdirections, each of the ears containing an aperture 360 structured andarranged to slideably receive one of the support members or guide rods354. As will be discussed in greater detail below, the secondinterlaminar member is movably supported by the upwardly extendingsupport members or guide rods, and the position of the secondinterlaminar member 341 relative to the first interlaminar member 325may be adjusted depending upon the dimensions of the specific spinalcolumn on which the system is installed and the range of motion desired.Once the position of the second interlaminar member 341 has beenselected, it is locked in place by a pair of set screws or othersuitable fastening means 362 extending through each of the ears 358 andadapted to releaseably engage the respective guide rod extendingtherethrough. A plurality of spaced-apart recesses 3624 adapted toreceive the ends of fastening means 362 may be formed in each of theguide rods to assist in positioning interlaminar member 341.

Increased stability to a spinal fixation system may be provided byemploying additional pedicle screws at selected locations in the system.For example, in accordance with another embodiment of the instantinvention, a spinal fixation system 400 with increased stability isdepicted in FIGS. 28-31. Of substantially the same configuration as thespinal stabilization 300 of the embodiment shown in FIG. 24, the system400 includes a pair of oppositely disposed brackets 402 each connectedto one of the support members or guide rods 354. Each bracket includesan aperture or slot formed therein, each slot being adapted to receiveat least one pedicle screw 340. As best shown in FIG. 29, apertures 406formed in the uppermost leg 352 of the first interlaminar support member325 and in the second interlaminar support member 341, respectively areeach likewise adapted to receive a pedicle screw 340. The reader willappreciate that the pedicle screws received in each of the apertures 404are positioned at a divergent angle with respect to one another, and thepedicle screws received in apertures 406 are positioned at a convergentangle with respect to one another, thus providing enhanced stability tothe stabilization system 400 by a uniform distribution of the structuralloading imposed thereon by the dynamics of the patient's post-operationmovements.

FIGS. 32 and 33 illustrate yet another embodiment 500 of a spinalstabilization system of the present invention structured to provideenhanced system and spinal stabilization. In this embodiment, each ofthe support members or guide rods 354 includes an ear or bracket member502 operatively connected thereto and extending transversely outwardlytherefrom in a direction generally away from the spinal column 312 andparallel and adjacent to an outwardly extending portion 504 of vertebra22. Each bracket has an aperture or eyelet 506 formed therein adapted toreceive a retention device 508 adapted to releaseably engage vertebraportion 504, each of the fasteners being oppositely disposed so as tocooperate with each other in applying a clamping force to the vertebraportion. In the embodiment shown, by way of example and not oflimitation, the fasteners are in the form of threaded fasteners orbolts, each having a knurled knob 510 attached thereto to facilitateinstallation tightening thereof; however, it is to be understood bythose skilled in the art that other forms of retaining devices such aspins, clamps and the like may be used without departing from the scopehereof. As described above with respect to an earlier embodiment, eachbracket 502 may include an inner surface or face (not visible in thefigures) which has sharp protrusions, or teeth Extending outwardlytherefrom adapted to engage and even imbed in outwardly, extendingportion 504 of vertebra 22 to prevent slippage following installation ofthe system.

Referring now to FIGS. 34-36, exemplary embodiments of interlaminarsupport members are illustrated in greater detail. Depending upon theapplication and the degree of support required to stabilize a particularpatient's spinal column, an interlaminar support member may be of agenerally rigid construction, a generally flexible construction, or itmay contain both generally rigid and generally flexible portions. Aswill be described below in greater detail, the rigid or flexibleportions of a support member are typically compressed by a separatecompression tool upon installation against first and second oppositelydisposed bone surfaces of adjacent vertebrae, such as vertebrae 14 and16 shown in FIGS. 6 and 7, and are retained in position by the elementsof the support system and locking means such as threaded fasteners, setscrews and the like, as described above.

According to an embodiment depicted in FIGS. 34(A)-(C), an interlaminarsupport member 520 comprises a generally T-shaped body 522 having aplurality of apertures 524 formed therein, each aperture adapted toreceive a pedicle screw or other suitable fastener (not shown) forsecuring the support member to a vertebra, and a plurality of recesses526, each recess being structured and arranged to adjustably receive asupport member (such as guide rod 28 of the embodiment of FIG. 1).Interlaminar support member 520 further includes a U-shaped body 528defined by an elastic midsection 530 and two spaced apart juxtaposedlegs 532, each leg, when in place in a spinal process, extendingsubstantially parallel to one another from the elastomeric midsection ina direction generally outwardly away from the spinal column. Theinterlaminar support member is intended to fuse the adjacent vertebrae.Accordingly, it is sized to be a tight fit, and the elastic propertiesof the U-shaped body 528 act as a spring or shock absorber in theinterface between the two vertebrae.

Referring to FIGS. 35(A)-(C), an interlaminar support member 540 isillustrated which includes a generally T-shaped body 542 having aplurality of apertures 544 formed therein, each aperture adapted toreceive a pedicle screw or other suitable fastener (not shown) forsecuring the support member to a vertebra, and a plurality of recesses546, again each recess being structured and arranged to adjustablyreceive a support member (such as guide rod 28 of the embodiment of FIG.1). The support member 540 further includes a U-shaped body 548 definedby an elastic midsection 550 and two spaced apart juxtaposed legs 552,the U-shaped body being operatively connected to the T-shaped body by aplanar arm member or bracket 554 positioned intermediate the legs 552.As described above with respect to the embodiment of FIG. 34, each leg,when in place in a spinal process, extends substantially parallel to oneanother and to the bracket 554 from the elastomeric midsection 550 in adirection generally outwardly away from the spinal column. At least oneof the legs further includes a wedge or V-shaped protrusion 556extending outwardly therefrom and transversely across an outer surface558 thereof, the protrusion being structured and arranged to resistivelyengage one of the oppositely disposed bone surfaces of adjacentvertebrae upon installation of the support system to prevent unintendeddisplacement thereof.

In accordance with another embodiment 570 of an interlaminar supportmember as shown in FIGS. 36(A)-(C), a generally T-shaped body member572, of similar configuration to the T-shaped body members of theembodiments of FIGS. 34 and 35, includes a generally J-shaped member 574extending transversely therefrom defined by a pair of oppositelydisposed sides 576 and curved upper and lower surfaces 578, 580 whichintersect to define a rounded or knob-shaped end portion 582. Thesupport member 570 is installed intermediate a pair of adjacentvertebrae by forcibly inserting the rounded end portion therebetween andthen rotating it about the end portion to a desired position, whereuponit is secured in place by pedicle screws and guide rods, as describedabove.

In particular aspects, the different elements of the system may beconfigured with tool engagement features in order to permit a surgeon tograsp the implant with a tool assembly or insertion tool to easeimplantation of the various components. For example, the insertion toolmay be configured as a pair of pliers or hemostats. As another example,a threaded portion of a tool assembly may reversibly secure to acomplementary threaded portion of the implant in order to easeimplantation. Accordingly, a tool assembly may be comprised of acannulated shaft with a retainer shaft housed substantially within, theretainer shaft further configured with a threaded portion at itsproximal end which may extend out of a proximal end of the retainershaft and a handle located and attached to a proximal end of theretainer shaft. The proximal end of the retainer shaft may have afeature that permits rotation of the retainer shaft via another tool,such as the mechanical arrangement that exists between a wrench and nut,in order to secure the tool assembly to the implant. After implantationof the implant the tool assembly may be decoupled and removed.

Referring now to FIGS. 37-39, a spinal stabilization system insertiontool apparatus, for ease of reference also referred to herein as aseating tool, adapted to install an interlaminar support member 520(FIG. 34) is shown generally at 600. Apparatus 600 comprises a firsttool 602 including a cylindrical body portion or cannulated shaft 604having an internal aperture 605 extending substantially longitudinallythe length thereof. The body portion further includes proximal anddistal ends 606, 608, the distal end comprising a pair of spaced apartlongitudinally extending segments 610 each terminating in a rounded ortapered end portion 612 structured and arranged to be releaseablyinserted into the support member 520, as shown in FIG. 37(D). One of thesegments 610 includes and alignment member 611 extending the lengththereof, the alignment member being structured and arranged to cooperatewith a guide member 613 formed in the interlaminar support member 520 toalign insertion tool apparatus 600 properly therein for preciseinsertion of the interlaminar member into a spinal column. Interlaminarsupport member 520 also includes a second alignment feature which isillustrated in the form of a knob or extension 533 having a channel orrecess 535 extending circumferentially thereabout, the knob and channelbeing adapted to receive portions of an installation apparatus, whichwill be discussed in greater detail below.

As shown in greater detail in FIGS. 37(B), 38 and 39, tool 602 includesat least one alignment guide 614 secured thereto and structured andarranged to be in operative alignment with an aperture 524. Thealignment guide is adapted to receive a fastener installation tool 616for installing a set screw or other fastening means 618 into theaperture 524 of the support member.

Referring again to FIG. 37, and specifically to FIG. 37(C), a secondseating tool 620 according on embodiment is shown which includes a bodyportion 622 having a proximal end 624 and a distal end 626, the distalend being tapered for ease of insertion into the internal aperture 605of first tool 602. The proximal end of the second tool includes athreaded portion 628 adapted to be threadably received by correspondingmating internal threads inside the proximal end 606 of the first tool602 so that upon insertion of the body portion 622 of the second toolinto the internal aperture 605 and in response to rotation thereof via ahandle 630 secured to the proximal end of the second tool, the taperedend 626 engages each of the end portions 612 forcing them into lockingengagement with the interlaminar support member 520 as shown in the sidesectional view of FIG. 37(D). The support member may then be deliveredto and inserted into the implantation site in a spinal column, and theset screws 618 may be inserted in alignment guides 614 and apertures 524and tightened by tool 616. After the insertion and securing operationsare completed, the second tool may be removed from the first tool bybacking out the threaded portion, thereby releasing the grip of the ends612 on the support member and permitting removal of the insertion toolapparatus from the support member.

Referring to FIGS. 40, 41(A) and 41(B), a third plier-like tool forinserting a spinal stabilization system configured in accordance withthe structure of the system 10 shown in the embodiment of FIG. 1 isillustrated at 650. In the configuration shown, the tool is designed todeliver parallel compressive forces to displace on member of the systema distance closer relative to another component. Alternatively, the toolmay be configured to deliver distractive forces to system componentswhereby one component of the system is displaced a distance furtherrelative to another component.

Tool 650 includes first and second arms 652, 654, each arm having a bodyportion 656, 658 pivotally interconnected at a midpoint 660 thereof, afirst end portion or handle 662, 664 and a second end portion 666, 668,each second end portion being pivotally pinned to a respective bodyportion by a pin 670. The second end portions 666, 668 are structurallysupported and cross linked to one another by a linkage mechanism, andeach further includes an ear or bracket member 674, 676 extendinglongitudinally outwardly therefrom, each ear being adapted to receive apin 678 for rotatably mounting an arm 680, 682 thereto respectively.Each arm includes a distal forked end portion 684, 686 having anaperture or recess 688, 690 formed therein, each recess being structuredand arranged to releaseably engage a portion of the spinal stabilizationsystem 10 for installation thereof on a patient's spinal column.

Referring to FIGS. 41(A) and 41(B), one forked end portion, end 684, isshown enlarged so that the features thereof may be understood in greaterdetail. Each end includes a pair of finger-like members 692, 694extending outwardly therefrom and general parallel to one another toform the aperture 688. The end portion further includes a recess 696which extends circumferentially around the aperture and is adapted toreceive a retainer, by way of example and not of limitation, a snap ringor other retaining device as is known in the art, to secure the end 684to a portion of a spinal stabilization system for purposes ofinstallation. By way of further example, aperture 688 and fingers 692,694 are adapted to fit over knob 533 and recess 535 on interlaminarsupport member 520 shown in FIG. 37 (A) and to cooperate therewith toachieve precise positioning and insertion of member 520 into a spinalcolumn.

FIGS. 42(A) and (B) illustrate the elements of a fourth tool or rodreducer 700 structured to be used in conjunction with the third tool 650and to cooperate therewith in the procedure of installing a spinalstabilization system 10. Similar in construction to the first tool 602,the fourth tool includes a cylindrical body portion or cannulated shaft702 having an internal aperture 704 extending substantiallylongitudinally the length thereof. The body portion further includesproximal and distal ends 706, 708, the distal end comprising a pair ofspaced apart longitudinally extending arms 710 each terminating in acurved or hooked member 712 structured and arranged to releaseablyengage a portion of the support system 10.

FIGS. 42(A)-(B) illustrate a moveable rod member 720 which cooperateswith cannulated shaft 702 to form the rod reducer 700. The rod memberincludes a body portion 722 having a proximal end 724 and a distal end726, the distal end being rounded or tapered for ease of insertion intothe internal aperture 704 of shaft 702. The proximal end of the rodmember includes a threaded portion 728 adapted to be threadably receivedby corresponding mating internal threads 730 inside the proximal end 724of the cylindrical body portion 702 so that upon insertion of the bodyportion 722 of the rod member into the internal aperture 704 and inresponse to rotation thereof via a handle 732 secured to the proximalend of the rod member, the tapered end 726 cooperates with hookedmembers 712 to engage and align an element of the spinal stabilizationsystem for installation on a spinal column, as will now be set forthwith greater specificity.

Referring to FIGS. 43-46, a method of installing a spinal stabilizationsystem 10 using the installation apparatus and tools hereinabovedescribed and the operating interrelationship and cooperation of thetools during the installation will now be described. As a generalbackground introduction, after the vertebrae in the portion of a spinalcolumn have been identified and exposed by a surgeon, an implant trialis used to determine an appropriate fit of an implant. Implant trials ofincreasingly larger size may be delivered into the implantation regionuntil an implant trial is chosen that appropriately fits the varioussurfaces of the implant trial against the boney surfaces of the laminaand spinous process. The implant trial may be forcibly delivered intothe implantation region by using a hammer or mallet to strike an impactplate (not shown) at a proximal end of the tool. Numerous trials andtemplates corresponding to various configurations and dimensions of thecomponents of the implant systems may be used during the course of theprocedure in order for a surgeon to select the appropriately dimensionedand configured implant system best suited to a particular patient.

Prior to surgical site or bone preparation, trial insertion, or implantplacement, a surgeon or other medical person may select a suitableprocedure to fixation or stabilize a portion of the spinal column. Theprocedure may include fusing the intervertebral joints with or withoutdelivering an implant in the joint space, e.g., an intervertebral bodyfusion device (“IBFD”). The procedure may alternatively or additionallyinclude placing pedicle screws or hooks in operable relation with spinalrods thereby forming a construct to which embodiments of the presentdisclosure may be operably coupled. If the surgeon selects a procedureinvolving delivery of an implant as disclosed herein up to and inengagement with a portion of the spinal column, the surgeon may selectan implant configuration for delivery into the posterior aspect of avertebral column of the patient including attachment to both a spinallamina and a pedicle screw and spinal rod construct based onpreoperative or intraoperative data. The data may be the result ofpost-processing of raw or other imaging data (e.g., CT or MRI DICOMfiles). The post-processing may include the use of a software program(e.g., 3DSLICER available from http://www.slicer.org) that may be usedfor medical image processing and 3D visualization of image data. Otherdata may include the patient's weight, activity level, and generalhealth.

The preoperative or intraoperative data may assist in the planning andselecting of desirable procedure trajectories (e.g., starting andstopping points on patient's soft tissue and near or within bonetissue), implant component types and dimensions (e.g., lengths, heights,widths, diameters, thread pitches, and angles relative to othercomponents), delivery tool configurations and dimensions, and bonepreparation tool types, dimensions, and configurations. A particularsystem for preparing and stabilizing the portion of the vertebral columnmay be selected, for example, for a hypermobile segment, which mayinclude one or more implant components or the entirety of the systemthat is resistant to the expected forces present at that particularpatient's spinal segment. The determination of fixation or stabilizationsufficiency may be calculated based on the patient's data and also onthe performance results of various bench and/or finite element analysis(“FEA”)-tested implant assembly configurations. For example, acalculated implant and/or screw trajectory may be considered anddetermined from certain patient imaging and post-processing data with anoverlaid implant assembly. Further, the implant assembly may be selectedto include a first and a second interlaminar component dimensioned andconfigured to extend as far anteriorly toward the spinal canal aspossible in order to center the interlaminar components as close to thecenter of the spinal column's axial compressive loading and in order toincrease total implant surface to bone surface contact area to betterdistribute the loading of the spine over a lower percentage of the totaljoint surface. This load distribution reduces the possibility of spinousprocess fractures and other complications.

Specific measurements and characteristics of the patient's anatomy mayinfluence the selection of a particular system or its components. Forexample, the patient's bone density may be measured at numerouslocations in proximity to and surrounding the elements of the implantassembly. Lower bone density (e.g., osteopenia, osteoporosis)corresponding to a T-score lower than −1, unstable spondylolistheses, orhypermobility may require the use of an implant assembly with a greaterrigidity or more points of fixation to the bone and or spinal rods.Additionally, the relative angles between the implant surfaces and screwor screws, and also the relative angles between multiple screws (e.g.,parallel, divergent, convergent) may be preselected based on thepatient's anatomy.

A comparison of the preoperative or intraoperative data (e.g., laminaand/or spinous process surface area, spinal segment mobility, loading,bone density, desirable anatomic pathways) and the selected implantassembly and bone preparation tools may be conducted to ensure orvalidate compatibility before the manufacture ships the implant systemand/or before the surgeon employs the system in a surgical procedure.After validation of the implant assembly and preparation tools, theselected assemblies may be shipped to the surgeon and the surgeon mayproceed with the surgical fusion procedure utilizing the selectedassemblies.

In particular embodiments, pre-operative imaging may be used tomanufacture custom implants to better match an individual patient'sanatomy or to correct a structural misalignment of the spinal column.The various surfaces or faces of the implant may be selected to matchthe contour of the bone surface to which the implant surface willcontact. For example, the surface or faces of the interlaminarcomponents which contact the lamina and spinous process may beconfigured to be generally planar or even concave to match the contourof a boney surface including wrapping a portion of the surface around agreater portion of the lamina or spinous process. In one aspect, thefaces or surfaces of the implant may be generally a surface negative ofthe surfaces to which said surfaces are desired to contact.

Referring now to FIG. 43, typically, a surgeon will employ a depthmeasuring device or a depth gauge (not shown), as is known in the art,to determine the depth from the guide rods 28 to the patient's spinalcolumn so that the size of the interlaminar support member for theintended implant location may be determined accurately. A spinalstabilization system 10 is positioned at the desired location along thecolumn at the insertion point. The spinal stabilization system 10includes a first interlaminar member 12 adapted to be positioned betweenadjacent first and second vertebrae in a spinal column (FIG. 6) and asecond interlaminar member 520 adapted to be positioned between thesecond vertebra and a third vertebra therein. Both the first and secondinterlaminar members are operatively interconnected with one another viasupport members or guide rods 28.

A first step entails the installation of pedicle screws 84 and securingdevices 80 attached to each at the proper locations in a spinal column.Guide rods 66, 68 may then be inserted into a respective securing device80 and secured thereto by set screws 82. At this point, any laminaand/or spinal process may be removed as necessary to decompress thevertebrae and measurements may be taken as described above. A transversemember (58 in FIG. 1) may then be attached to the spinal or guide rods66, 68, and a first interlaminar support member 12 may be placed at thedesired location along the spinal column. The set screws 82 securing theguide rods 66,68 are tightened, and lateral images and depth gauges areemployed to measure the distances required for precise insertion of theinterlaminar member. Similar measurements are made for the secondinterlaminar member 520 and it is positioned over the spinal column atthe intended insertion point.

Referring now to FIGS. 44 and 45, rod reducer tool 700 is attached toone of the guide rods 28 with arms 710 positioned on either side of theinterlaminar member 520 thereby straddling it and each hooked member 712operatively connected to the guide rod. By rotating handle 720, tool 700aligns guide rod, interlaminar member 520, set screw alignment guide 614and the patient's spinal column properly for precise insertion of themember therein and installation and tightening of a set screw or othersuitable fastening means by tool 616, as will be described below.

At this time, compression/insertion tool 650 is attached to thestabilization system 10 with one forked end 684 in operative engagementwith leg member 48 of interlaminar member 12, and the other forked endin operative engagement with knob 533 and recess 535 on interlaminarmember 520, whereby upon activation of the repressor 650, eithercompressive or distractive forces are applied to each of theinterlaminar members 12 and 520 to position them along rods 28 at apreferred spacing as determined by the measurements taken earlier.

The seating tool 620 is now positioned over alignment guide 613 insupport member 520, as best viewed in FIG. 46, and secured thereto byexpanding members 612 into operative engagement with the interlaminarsupport member. The support member may then be delivered to and insertedinto the implantation site in a spinal column, and the set screws 618may be inserted in alignment guides 614 and apertures 524 and tightenedby tool 616. After the insertion and securing operations are completed,the various tools may be removed from the support member and otherelements of the spinal stabilization system and the incisions may besutured to begin the patient's healing and recovery process.

Changes may be made in the above methods and systems without departingfrom the scope hereof. It should thus be noted that the matter containedin the above description and/or shown in the accompanying figures shouldbe interpreted as illustrative and not in a limiting sense. Thefollowing claims are intended to cover all generic and specific featuresdescribed herein, as well as all statements of the scope of the presentsystems and methods, which, as a matter of language, might be said tofall there between.

What is claimed is:
 1. A stabilization system for stabilizing multiplelevels of a patient's spine, the patient having a head, a pelvis, and aspinal column operatively connected at a caudal end thereof to thepatient's pelvis and operatively connected at a cephalad end thereof tothe patient's head, the spinal column including a plurality ofoperatively interconnected vertebrae positioned at multiple levelsintermediate the caudal and cephalad ends thereof, each of the pluralityof vertebrae being separated from an adjacent vertebra by anintervertebral space formed between the adjacent vertebrae, the systemcomprising: a first interlaminar member adapted to be positioned in anintervertebral space intermediate a first one of the plurality ofoperatively interconnected vertebrae and a second adjacent one of theplurality of operatively interconnected vertebrae, the firstinterlaminar member including a U-shaped body having a midsection, andtwo spaced apart end portions, and a pair of juxtaposed legs extendinggenerally parallel to one another from one of the respective ends in adirection generally outwardly away from the spinal column when the firstinterlaminar member is implanted; a pair of guide rods secured to thefirst interlaminar member and extending in a direction upwardlytherefrom generally parallel to one another; a second interlaminarmember adapted to be positioned between the second vertebra and a thirdvertebra positioned adjacent to and above the second vertebra in thespinal column, the second interlaminar member being structured andarranged to be slideably supported by the pair of guide rods whereby theposition of the second interlaminar member relative to the firstinterlaminar member may be selectively adjusted in response to adimension of the spinal column and a preferred preselected range ofmotion thereof; and a support structure structured and arranged tosecure the stabilization system to the patient's spinal column wherebymultiple levels of the plurality of operatively interconnected vertebraeare stabilized, the support structure including a plurality oftransversely extending cross members which span the patient's spinalcolumn when the first interlaminar member is implanted, eachtransversely extending cross member including an elongate body portionhaving a midpoint operatively connected to the first interlaminar memberand first and second free end portions, wherein at least two of theplurality of transversely extending cross members are operativelyinterconnected to one another at the midpoints thereof.
 2. Thestabilization system of claim 1 further including a connector secured toeach of the first and second free end portions of each of the pluralityof transversely extending cross members.
 3. The stabilization system ofclaim 2 wherein each of the connectors further includes an apertureformed therein for receiving a free end portion of one of the pluralityof transversely extending cross members.
 4. The stabilization system ofclaim 3 wherein each of the connectors includes a fastener adapted tohold the connector in a preselected position on the free end portion ofa transversely extending cross member.
 5. The stabilization system ofclaim 4 further including first and second support members operativelyconnected to the first and second free end portions of each of thetransversely extending cross members respectively, each of the first andsecond support members having an upper end and a lower end, each of theupper and lower ends being adapted to be secured to at least one of theplurality of operatively interconnected vertebrae of the spinal column.6. The stabilization system of claim 5 wherein the connector on thefirst free end portion of each of the transversely extending crossmembers is structured and arranged to adjustably receive the firstsupport member therein, and the connector on the second free end portionof each of the transversely extending cross members is structured andarranged to receive the second support member therein.
 7. Thestabilization system of claim 6 wherein each of the upper and lower endsof the first and second support members has a securing device slideablypositioned thereon, each securing device being releasably secured to arespective upper or lower end by a fastener.
 8. The stabilization systemof claim 7 wherein each securing device is structured and arranged toreceive a pedicle screw, each pedicle screw being adapted to be securedto a respective one of the plurality of operatively interconnectedvertebrae.
 9. The stabilization system of claim 1 wherein the firstinterlaminar member and the support structure are integrally formed by asingle piece of material.
 10. The stabilization system of claim 1wherein the midsection of the U-shaped body of the first interlaminarmember is elastic.
 11. The stabilization system of claim 1 wherein thesecond interlaminar member includes a body portion having a preselectedthickness, the preselected thickness being selected based upon thespacing between the second vertebra and the third vertebra.
 12. Thestabilization system of claim 1 further including an intervertebral bodyfusion device adapted to be inserted between the first one of theplurality of operatively interconnected vertebrae and the secondadjacent one of the plurality of operatively interconnected vertebrae.13. The stabilization system of claim 12 further including anintervertebral body fusion device adapted to be inserted between thefirst one of the plurality of operatively interconnected vertebrae and afourth vertebra positioned adjacent to and below the first vertebra inthe spinal column.
 14. The stabilizer system of claim 13 furtherincluding an intervertebral body fusion device adapted to be insertedbetween the fourth one of the plurality of operatively interconnectedvertebrae and a fifth vertebra positioned adjacent to and below thefourth vertebra in the spinal column.
 15. A stabilization system forstabilizing multiple levels of a patient's spine, the patient having ahead, a pelvis, and a spinal column operatively connected at a caudalend thereof to the patient's pelvis and operatively connected at acephalad end thereof to the patient's head, the spinal column includinga plurality of operatively interconnected vertebrae positioned atmultiple levels intermediate the caudal and cephalad ends thereof, eachof the plurality of vertebrae being separated from an adjacent vertebraby an intervertebral space formed between the adjacent vertebrae, thesystem comprising: a first interlaminar member adapted to be positionedin an intervertebral space intermediate a first one of the plurality ofoperatively interconnected vertebrae and a second adjacent one of theplurality of operatively interconnected vertebrae, the firstinterlaminar member including a U-shaped body having a midsection, andfirst and second spaced apart end portions, and a pair of juxtaposedlegs, one of the pair of juxtaposed legs being operatively connected tothe first spaced apart end portion and the other of the pair ofjuxtaposed legs being operatively connected to the second spaced apartend portion, the pair of juxtaposed legs extending generally parallel toone another from the respective first and second end portions in adirection generally outwardly away from the spinal column, when thefirst interlaminar member is implanted; a pair of guide rods secured tothe first interlaminar member and extending in a direction upwardlytherefrom generally parallel to one another; a second interlaminarmember adapted to be positioned in an intervertebral space between thesecond vertebra and a third vertebra positioned adjacent to and abovethe second vertebra in the spinal column, the second interlaminar memberbeing slideably supported by the pair of guide rods whereby the positionof the second interlaminar member relative to the first interlaminarmember may be selectively adjusted in response to a dimension of thespinal column and a preferred preselected range of motion thereof; and asupport structure structured and arranged to secure the stabilizationsystem to the patient's spinal column whereby multiple levels of theplurality of operatively interconnected vertebrae are stabilized, thesupport structure including a plurality of transversely extending crossmembers which span the patient's spinal column when the firstinterlaminar member is implanted, each of the plurality of transverselyextending cross members including an elongate body portion having amidpoint operatively connected to the first interlaminar member andfirst and second end portions, wherein at least two of the plurality oftransversely extending cross members are operatively interconnected toone another at the midpoints thereof, the first and second ends of eachof the plurality of transversely extending cross members having arespective connector secured thereto, each connector being structuredand arranged to adjustably receive and secure a respective first andsecond support member to the respective first and second ends of each ofthe plurality of transversely extending cross members.
 16. Thestabilization system of claim 15 wherein each of the first and secondsupport members has an upper end and a lower end, each of the upper andlower ends being adapted to be secured to at least one of the pluralityof operatively interconnected vertebrae of the spinal column.
 17. Thestabilization system of claim 15 wherein the second interlaminar memberincludes a body portion having a preselected thickness, the preselectedthickness being selected based upon the spacing between the secondvertebra and the third vertebra.
 18. The stabilization system of claim17 wherein the second interlaminar member is adapted to be placedbetween the second vertebra and the third vertebra where the spacingtherebetween is larger than the thickness of the second interlaminarmember.
 19. The stabilization system of claim 17 wherein the secondinterlaminar member is adapted to be wedged in the spacing between thesecond vertebra and the third vertebra where the spacing therebetween issmaller than the thickness of the second interlaminar member.
 20. Thestabilization system of claim 1 wherein the pair of juxtaposed legs ofthe U-shaped body portion of the first interlaminar member are spacedapart a preselected distance, the distance being determined by thespacing between the first one of the plurality of operativelyinterconnected vertebrae and a second adjacent one of the plurality ofoperatively interconnected vertebrae.
 21. A stabilization system for apatient's spine, the patient having a head, a pelvis, and a spinalcolumn operatively connected at a caudal end thereof to the patient'spelvis and operatively connected at a cephalad end thereof to thepatient's head, the spinal column including a plurality of operativelyinterconnected vertebrae positioned at multiple levels intermediate thecaudal and cephalad ends thereof, each of the plurality of vertebraebeing separated from an adjacent vertebra by a space formed between theadjacent vertebrae, the system being adapted to stabilize multiplelevels of vertebrae, the system comprising: a first interlaminar memberadapted to be positioned in a space intermediate a first one of theplurality of operatively interconnected vertebrae and a second adjacentone of the plurality of operatively interconnected vertebrae, the firstinterlaminar member including a U-shaped body having a midsection, twospaced apart end portions, and a pair of juxtaposed legs, each leg beingoperatively connected to a respective one of the two spaced apart endportions of the U-shaped body, the legs extending generally parallel toone another in a direction generally outwardly away from the spinalcolumn when the first interlaminar member is implanted; a pair of guiderods secured to the first interlaminar member and extending generallyparallel to one another in a direction upwardly from an upper one of thepair of juxtaposed legs toward the cephalad end of the patient's spinewhen the first interlaminar member is implanted; a second interlaminarmember adapted to be positioned between the second vertebra and a thirdvertebra positioned adjacent to and above the second vertebra in thespinal column, the second interlaminar member being structured andarranged to be slideably supported by the pair of guide rods whereby theposition of the second interlaminar member relative to the firstinterlaminar member may be selectively adjusted in response to adimension of the spinal column and a preferred preselected range ofmotion thereof; and a support structure structured and arranged tosecure the stabilization system to the patient's spinal column, thesupport structure including: a plurality of transversely extending crossmembers spanning the patient's spinal column when the first interlaminarmember is implanted, each transversely extending cross member includingan elongate body portion having a midpoint and first and second free endportions, the midpoint of at least one of the transversely extendingcross members being operatively connected to the first interlaminarmember, at least two of the plurality of transversely extending crossmembers being operatively interconnected to one another at the midpointsthereof; a first securing device attached to each of the first andsecond end portions of each of the plurality of transversely extendingcross members; first and second support members operatively connected bya respective one of the first securing devices to a respective first andsecond end portion of each of the at least two transversely extendingcross members, each of the first and second support members having anupper end and a lower end, each of the upper and lower ends beingadapted to be secured to a respective one of the plurality ofoperatively interconnected vertebrae of the spinal column when the firstand second interlaminar members are implanted; and a plurality of secondsecuring devices adapted to secure the first and second support membersto the patient's spine, one of the plurality of second securing devicesbeing slideably positioned on the upper end of each of the first andsecond support members, and one of the plurality of second supportmembers being slideably positioned on the lower end of each of the firstand second support members, each of the second securing devices beingadapted to receive a bone screw, each bone screw being structured andarranged to be threadably secured to one of the plurality of operativelyinterconnected vertebra of the patient's spinal column when the firstand second interlaminar members are implanted.
 22. The system of claim21 further including a plurality of third securing devices, one of theplurality of third securing devices being positioned in each of theplurality of second securing devices and being adapted to secure each ofthe first and second securing devices to the respective upper and lowerends of each of the support members.
 23. The system of claim 22 whereineach of the plurality of third securing devices comprises a set screw.24. The stabilization system of claim 21 wherein the second interlaminarmember includes a body portion having a preselected thickness, thepreselected thickness being selected based upon the spacing between thesecond vertebra and the third vertebra.
 25. The stabilization system ofclaim 24 wherein the second interlaminar member is adapted to be placedbetween the second vertebra and the third vertebra where the spacingtherebetween is larger than the thickness of the second interlaminarmember.
 26. The stabilization system of claim 24 wherein the secondinterlaminar member is adapted to be wedged between the second vertebraand the third vertebra where the spacing therebetween is smaller thanthe thickness of the second interlaminar member.
 27. The stabilizationsystem of claim 21 wherein the pair of juxtaposed legs of the U-shapedbody portion of the first interlaminar member are spaced apart apreselected distance, the distance being determined by the spacingbetween the first one of the plurality of operatively interconnectedvertebrae and a second adjacent one of the plurality of operativelyinterconnected vertebrae.